This project deals with work on two different biochemical problems. First, it is concerned with the mechanism of folding of small globular proteins. Work to date suggests that the rate-determining step in protein folding has to do with the cis-trans isomerism of the peptide bonds of proline residues. We are attempting to provide definitive evidence for this hypothesis by two different experimental approaches: Kinetic studies of proteins and model compounds and direct NMR visualization of the isomerism process. Second, the project deals with numerous aspects of structure-function relationships in erythrocyte membranes. This problem is being approached by utilizing various structural methods including scanning calorimetry and spectroscopic approaches and various studies of membrane transport.